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<td><b><dl><dt>Berkeley DB Reference Guide:<dd>Upgrading Berkeley DB Applications</dl></b></td>
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<p align=center><b>Release 3.0: function arguments</b></p>
<p>In Berkeley DB 3.0, there are no longer separate structures that represent
each subsystem (for example, DB_LOCKTAB or DB_TXNMGR), and an overall
<a href="../../api_c/env_class.html">DB_ENV</a> environment structure.  Instead there is only the
<a href="../../api_c/env_class.html">DB_ENV</a> structure.  This means that <a href="../../api_c/env_class.html">DB_ENV</a> references
should be passed around by your application instead of passing around
DB_LOCKTAB or DB_TXNMGR references.</p>
<p>Each of the following functions:</p>
<blockquote><pre>lock_detect
lock_get
lock_id
lock_put
lock_stat
lock_vec</pre></blockquote>
<p>should have its first argument, a reference to the DB_LOCKTAB structure,
replaced with a reference to the enclosing <a href="../../api_c/env_class.html">DB_ENV</a> structure.  For
example, the following line of code from a Berkeley DB 2.X application:</p>
<blockquote><pre>DB_LOCKTAB *lt;
DB_LOCK lock;
	ret = lock_put(lt, lock);</pre></blockquote>
<p>should now be written as follows:</p>
<blockquote><pre>DB_ENV *dbenv;
DB_LOCK *lock;
	ret = lock_put(dbenv, lock);</pre></blockquote>
<p>Similarly, all of the functions:</p>
<blockquote><pre>log_archive
log_compare
log_file
log_flush
log_get
log_put
log_register
log_stat
log_unregister</pre></blockquote>
<p>should have their DB_LOG argument replaced with a reference to a
<a href="../../api_c/env_class.html">DB_ENV</a> structure, and the functions:</p>
<blockquote><pre>memp_fopen
memp_register
memp_stat
memp_sync
memp_trickle</pre></blockquote>
<p>should have their DB_MPOOL argument replaced with a reference to a
<a href="../../api_c/env_class.html">DB_ENV</a> structure.</p>
<p>You should remove all references to DB_LOCKTAB, DB_LOG, DB_MPOOL, and
DB_TXNMGR structures from your application, they are no longer useful
in any way.  In fact, a simple way to identify all of the places that
need to be upgraded is to remove all such structures and variables
they declare, and then compile.  You will see a warning message from
your compiler in each case that needs to be upgraded.</p>
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